It was a tough day for starting quarterbacks in the AFC South.
Coach Ken Whisenhunt said after a 16-11 loss to the Jets on Sunday that doctors popped Locker's shoulder back in.
Locker could have returned if needed, but would have only been able to hand off. It leaves the Titans with Charlie Whitehurst their only healthy quarterback.
The Titans (2-12) visit the Jaguars on Thursday night, leaving Locker a short week to try to recover. Whisenhunt said he would have to talk to the trainer to see if Locker can finish the season. Locker was starting with rookie Zach Mettenberger already out with a sprained right shoulder.
Also, Houston quarterback Ryan Fitzpatrick was carted off the field with an air cast covering his left leg early in the second quarter at Indianapolis.
Fitzpatrick was injured on a 2-yard run with 13:29 to go.
Fitzpatrick opened the season as Houston's starter, was replaced by Ryan Mallett and then reclaimed the starting job three weeks ago when Mallett went down with a season-ending injury.
Coach Bill O'Brien would not confirm reports that the leg was broken.
Robert Griffin III replaced him and finished 18 of 27 for 236 yards. He also ran five times for 46 yards.
San Francisco running back Frank Gore left with a concussion after falling to the turf after throwing a block in the second quarter against Seattle.
Also in the game, 49ers middle linebacker Chris Borland and Seattle left tackle Russell Okung (chest) were both injured on Eric Reid's interception return on the final play of the first half. Okung suffered a chest-wall bruise and was taken to a hospital for further examination and released.
Haden walked to the locker room for further evaluation and tests early in the second quarter, with the Browns trailing 17-0. He didn't return, and following the game, Browns coach Mike Pettine said his best defensive player would have the MRI.
The Browns also lost rookie cornerback Justin Gilbert with a concussion. He went out late in the first half, further depleting Cleveland's banged-up secondary. The No. 8 overall pick in this year's draft, Gilbert had been playing better of late. He returned an interception for a touchdown last week against Indianapolis.
Ravens safety Terrence Brooks hurt his right knee on the game's first play against Jacksonville and is likely lost for the season, coach John Harbaugh said. Jaguars linebacker Ryan Davis (hip) and Ravens defensive back Asa Jackson (knee) left early and did not return.
Bulaga was hurt early in the fourth quarter while attempting to make a tackle after Bills safety Bacarri Rambo intercepted Aaron Rodgers for a second time. Bulaga was on the field for several minutes before being helped off.
In other injury news:
-Detroit Lions offensive lineman LaAdrian Waddle was carted off the field in the third quarter against Minnesota with a left knee injury. Waddle, in his second NFL season, has been a starter for the Lions, but he's been limited by injuries, including a calf issue early in the season. Lions linebacker Ashlee Palmer left in the first half with a quadriceps injury.
AP NFL website: www.pro32.ap.org and http://twitter.com/AP-NFL